colchiro I think I have been hijacking some of the threads lately..pls excuse me.. im really stressing

I am only using the first click on the d17 efie (only 0.050v boost) I still seem to be in open loop..
I tried 2 clicks (100mv and 4 clicks 200mv) and had similar results

I know because my economy always falls to 13.5ltrs/100km (21mpg).. Without HHO I get 12.5l/100 (23mpg)..
The best I have ever had with HHO has been 12l/100 (24mpg) which was without IAT mods and 160mv on a simple battery type booster efie.

I also have a pot in parallel with the IAT set at 8.5kohm which calculates to about a 15degC increase. I have detached the air funnel so the air is coming from inside the engine compartment.

Although my O2 seems to be operating properly ie. jumps to 0.9 after revving the motor, etc. I know when I measured the resistance for the heater element it was not to spec.

I hadn't even noticed. Best to keep all your info in one thread tho so people helping you don't have to search for you.

How many miles on your o2's? They need to be replaced before 100,000 miles.

Sounds like you don't have an efficient cell or have leaks. You can check for leaks with soapy water and a brush, looking for bubbles. You should also measure it for output. At least 1 LPM is needed per liter of engine displacement. I suspect that's your problem.

Thanks colchiro
Not sure how old the o2 sensor is but I have about 240,000km on the clock and the O2 in the car is an aftermarket so I know its been replaced at least once.

The problem I have is that no matter what setting I have on the efie I cannot get the car to even sound different, let alone cough or splutter...

Will check for leaks.. I am only estimating but possibly about 1.5ltrs/min around 18 amps so it is on the low side. I had around 2 ltrs/min at just over 30 amps but I felt this was too high a load for the motor.

I got under the car and took the signal from the computer side of the o2 sensor. I confirmed I had the right wires by monitoring on a multimeter and small oscilliscope then checked the ecu to make sure the signal was getting there also

Its a home made Smack Gen II that I have split in half and added an extra plate. This is what it looked like when I made it but now its covered in goop

Nice lookin' cell. If I had one like that, it'd be hanging on the wall, not hidden my my vehicle. (The red background doesn't hurt any either.)

Ok sounds like you probably have the efie installed correctly and a good cell. What size engine? Are you getting at least 1 lpm per liter engine displacement?

Maybe you can roughly estimate the miles on the o2, if the previous owner installed the o2 sensor. Mike swears that's fixed a lot of marginal installations. The digital efie works better with marginal o2's, but it's still best to upgrade the sensor (garbage in-garbage out). We start to think about replacing them by 60k miles and definitely by 100k miles, so maybe time to replace them anyway.

Sounds like a freq-based MAF sensor, which is referenced in my Tuning for Mileage link and the theory behind it might be covered in my Autoshop link under "pressure" or "air-flow" sensors. I don't recall.

I have been struggling with this same problem, as many are. I wanted to try an adjustable choke (electronic, not mechanical) to modify the signal, but haven't gotten that far yet. The only way that I have successfully modified the signal to date was to either physically enlarge the throat of the intake, or restrict the airflow across the film. The GM's have a nice screen in front of the MAF that I place foil tape on to block some of the airflow to the sensor. It has to be small though, and it is a tedious process to get the right size and placement.
I have found some correlation between the MAF and the MAP, I can get the MAF to drastically change the fuel delivery by altering the MAP, but the ECU is what changes the MAF, and it takes some driving time for this process to make the changes. I think you're on the right track by trying to modify the frequency. I wish I had more time to experiment with it.